In my U.S. Pat. No. 2,889,072, there is disclosed square tote or lug boxes that may be switched from a nesting condition to a stack condition or vice versa, by rotation of either box 90 degrees about a vertical axis. Earlier systems using rectangular (as distinguished from square) boxes required rotation of 180 degrees (around a vertical axis through the box) to go from an initial stacking or nesting condition to the opposite position. The defects in the latter system are discussed in my above-mentioned patent. That patent also discusses in detail the advantages of using square boxes in a field or at a cannery during loading, trucking and unloading of such boxes.
The patent also discusses the advantages of handling of such boxes with a fork-lift truck without the need of bottom support pallets that are required with conventional, straight-sided wooden boxes. Specifically, the patent also describes the problems of handling rectangular boxes full of fruit that must be rotated 180 degrees about a vertical axis to go from a nesting to a stacking condition or vice versa. For such handling, it is necessary to pick up the box, rotate 90 degrees, set it down, pict it up again and rotate another 90 degrees. A particular advance of the patent over previous box systems was to require only one 90 degree rotation of any box to go from nesting to stacking or the reverse. However, errors could occur in attempts to nest or stack one box with the other since every box will both nest or stack.
In general, neither of the above discussed box rotation systems have become fully commercial over the past 20 years, even though these systems would have solved many of the basic storage and handling problems of pallet-supported wooden boxes. It is believed that a primary reason that commercial success was not achieved is the need to orient each box correctly either to stack or nest and the possibility of errors inherent in an uncoded system, whether the boxes are square, rectangular or other polygonal shapes. A particular disadvantage of conventional wooden boxes, either stacked on each other or loaded on pallets, occurs when they are full of soft fruits or vegetables that can be damaged if the boxes are misplaced in loading or shift during transportation. Under these conditions not only is the fruit damaged but also the tines of the fork lift frequently cannot gain access to the bottom of the box or the support pallet to right or unload the box. This then delays or ties up unloading until auxiliary equipment, usually another fork lift or a hoist, is brought in to complete unloading. The present invention clearly obviates these problems.